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```Easy-Lift Extension Ladder

Makej Projects

Written By: Martin Schmidt

SUMMARY

For me, a big drawback of extension ladders is that it usually takes a lot of effort to extend
them to the desired height. This is partly due to the way in which they are rigged. Typically,
the ladder is operated by a rope which is fastened to the bottom of the extending part of the
ladder. The rope runs through a pulley at the top of the stationary part and back down to
ground level for the operator to grasp. This simple arrangement is inexpensive to
manufacture but it requires a force on the rope which is equal to the weight of the moving
portion of the ladder. If the ladder is large, or if the moving parts have a high degree of
friction, the ladder can be very difficult to extend when it is standing upright. This, in turn,
makes it difficult to control the ladder and compromises safety.

I recently obtained an old extension ladder for free. Its rope was missing and while I was
measuring it to find out how much rope I needed to buy it occurred to me that I could convert
the ladder to a double-pulley system which would make it easier and safer to use.

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Step 1 — Analyzing the mechanism

• In the stock extension ladder, the
single pulley simply translates
motion from one direction to
another. The force required to
extend the ladder is equal to the
portion.

• In a double-pulley system,
force. The rope needs to be pulled
twice as far, but the force required
is equal to only half of the weight
being lifted.

• The second pulley will be installed
at the bottom of the moving portion
of the ladder. One end of the rope
will then be fastened to the top of
the stationary portion. The rope will
run down the ladder and through
the new pulley at the bottom of the
moving portion, back up and
through the original pulley at the
top of the stationary portion and
then down to the operator at ground
level.

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Step 2 — Parts required

• Pulley

• Bolt and nylock nut to fit ring on
pulley

• Flat washers to fit bolt

• Metal strap

• Rope (approximately three times

Step 3 — Making the retaining strap

• I used a strap originally designed to hold a 2" metal downspout to the wall of a house. The
strap was exactly the length I needed. The holes in the strap had to be enlarged to 3/8" to
accommodate the bolt.

• Bend the strap around the bottom rung of the moving portion of the ladder.

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Step 4 — Installing the pulley assembly

t Put a washer on the bolt, slip the ring of the pulley between the ends of the strap and insert
the bolt.

• Install another washer and the nut. Tighten the assembly so that the pulley is held in an
upright position when the ladder is stood on end.

• Note: Make sure that the pulley does not hit the rungs on the other half of the ladder
as the ladder is extended and retracted. Bend the strap as necessary to provide
clearance.

Step 5 — Installing the rope

• Tie the rope to the top rung of the stationary portion of the ladder, next to the original
pulley. Use a bowline knot or something similar.

• Thread the rope between the two halves of the ladder to the bottom and run it through the
newly-installed pulley.

• Thread the rope along the same path back to the top of the ladder and through the original
pulley.

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Step 6 — Finishing the conversion

• Run the rope down the backside of the ladder to the bottom and cut it to length.

• If desired, leave some extra length so that you can tie the rope to the bottom rung of the
stationary portion of the ladder. This helps keep the rope under control when you are

• If you are using a synthetic rope as I did, heat-seal the end of the rope to keep it
from unraveling. Matthew Cox has supplied this guide for sealing the end of the
rope.

Gr

The rope on a stock extension ladder is often polypropylene or something similar. It is tough but
not particularly flexible. I selected a woven nylon rope which is abrasion-resistant and very
supple.

After finishing the modification I stood the ladder upright and tested it. Extending the ladder was
almost effortless. I've used it on numerous occasions since then and I'm very pleased with it.

last generated on 2012-10-30 10:48:59 PM.

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